The U.S. Treasury Department on Thursday issued new legal guidance that might prevent Apple from recouping any back taxes owed in Ireland by claiming them against taxes it would normally pay in America.

In the wake of the European Commission's ruling against tax deals between Apple and Ireland, the finance ministers of several other European countries are reportedly considering a share of the iPhone maker's back taxes.

On Tuesday, the European Commission handed down its biggest tax penalty yet, ordering Apple to pay 13 billion euros ($14.5 billion) in back taxes -- but both Ireland and Apple are appealing the ruling.

On Tuesday the European Commission will find against Ireland's tax arrangements with Apple, and ask the country to collect over 1 billion euros ($1.119 billion) in back taxes, a report claimed on Monday.

The U.S. Treasury Department issued a special white paper on Wednesday, threatening that it will "consider potential responses" should the European Commsission demand that Ireland collect billions of euros in back taxes from Apple.

In a joint press conference in Paris on Tuesday, the interior ministers of France and Germany called on the European Commission to enact laws that would give countries on-demand access to encrypted communications under some circumstances.

Following a meeting with European Commission chief Margrethe Vestager on Tuesday, Irish Finance Minister Michael Noonan said he expects the EU antitrust regulator to reach a decision in its investigation into Apple's Ireland tax agreements by September or October.

U.S. Treasury Secretary Jacob Lew is reportedly meeting with the head of the European Union's antitrust efforts, Margrethe Vestager, ahead of an anticipated ruling on whether the Irish government will have to collect back taxes from Apple.

As anticipated, the European Commission on Wednesday pressed a new set of antitrust charges against Google, saying the company is hindering competition by locking in certain Android apps, or even versions of Android, despite it being an open-source operating system.

There's no way of telling when the European Commission will conclude its investigation into Apple's Irish tax deals, simply because the huge amount of data involved, the Commission's competition head said on Monday.

Apple is "committed to Ireland," whatever might happen in an European Commission investigation into Irish tax deals, the company's VP of European operations said to a European Parliament panel on Tuesday.

Apple, Google, IKEA, and McDonald's will together face a European Parliament hearing on Wednesday, called amid European Commission investigations into whether such multinationals were given preferential tax deals by some nations.

The European Commission is not unfairly targeting American corporations like Apple when it comes to cracking down on tax deals constituting illegal state aid, according to the E.U.'s competition head, Margrethe Vestager.

Earlier on Thursday Apple CEO Tim Cook attended a private meeting in Brussels with Margrethe Vestager, the head of the European Commission's antitrust efforts, presumably in an attempt to diminish the chances of owing billions in back taxes because of the company's Irish tax deals.